The present invention concerns in-line roller skates, i.e. with all the wheels disposed in a line lengthways, provided with a braking device which can be actuated by a movement of the cuff of the skate boot or by the skater""s leg.
Given that braking roller skates cannot, as a rule, occur in the same manner as braking on the side with an ice skate boot because of the risk of damaging the bearings of said wheels, a braking device preferably has to be added. Without such a braking device, the user of the skates has to brake by turning sharply and steeply which is similar to slowing down making the braking distance quite long, or by T braking with the rubber of the wheels by dragging one of the skates behind in a transverse position with respect to the direction of movement of the skate. It is clear that T braking does not require any particular mechanism, but it can only be used at relatively low speeds and also rapidly wears out the wheels while still having a long braking distance.
The braking device is usually placed on one of the two skates so as to be able to brake for example by placing one leg in front of the other, i.e. like scissors. The device acts directly on the wheels or on the ground.
One example of a currently used braking device consists in placing at the front or back of the skate an elastomeric pad so that it comes into contact with the ground to brake. Mounting such pads is common, since they are inexpensive. However, the fact of braking via pressure on the ground with an elastomeric pad is not very comfortable and the braking distance to a complete stop is relatively long.
Other braking device embodiments, which have mostly been protected by a patent, have been proposed without however being perfectly suited to roller skating.
One of the embodiments consists in a device braking all the wheels of both skates which includes discs secured to the frame placed on the outer sides between the wheels and the frame. By positioning the legs in an X with both feet parallel and perpendicularly to the line of skating, the wheels move laterally against the discs and cause braking. This method has a serious drawback, since positioning the legs in an X does not allow the stability required at the moment of braking to be improved. The only way to brake with sufficient stability being to place the legs in a scissor position which is not permitted by such a device.
U.S. Pat. No. 5,411,276 discloses, for example, an embodiment wherein the user brakes on a lateral surface of the two back wheels of one of the in-line skates with a brake actuated by a control lever which is manually actuated and connected by cable to the skate brake rod assembly. One drawback of this embodiment lies essentially in the fact that the skater has to permanently hold the control lever in his hand to be able to make the skates brake which also only works on the rolling surface of the rear wheels.
In place of such a braking control lever, an improvement to this control has consisted in providing one of the skates with a control lever, placed on the rear of the skate. When the skate boot is inclined backwards, the lever swings acting on a brake rod assembly placed on the frame of the skate to brake.
WO Patent No. 98/40133 discloses such a braking device wherein a rod includes openings housing the wheels and is placed on the axle of said wheels. The rod is pushed forwards against return means by a lever articulated on the rear of the boot so that the edges of the openings come into direct contact with the rolling surface of the wheels. A major drawback of having to brake by direct contact on the wheel lies in the fact that significant heating tends quickly to damage the wheels which are themselves already sufficiently subjected to wear via their contact with the ground.
In order to avoid having to brake via direct contact on the rolling surface of said wheels, embodiments have concerned the addition of discs made of a material, particularly metal, on a lateral surface of the wheels and brake pads carried by an element connected to the frame which is moved in the direction of the discs in order to brake.
A disc braking device for in-line roller skates is disclosed in U.S. Pat. No. 5,657,999. It includes two discs mounted on each side of the two central wheels, two rods rotatably mounted on the frame about an axis of rotation perpendicular to the axles of the two wheels carrying brake pads, a control lever for the rod rotatably mounted under the boot about an axis of rotation parallel to the axles of the wheels, a pedal housed inside the boot so as to be able to actuate the lever and the rods against return means to bring the pads into contact with the discs in order to brake. It can easily be seen that one drawback of such an embodiment lies in the fact that it is necessary for the toes to act on an inner pedal with significant force in order to brake which makes the use of such skates uncomfortable.
WO Patent No. 97/11759 discloses in-line roller skates with a disc braking device actuated using a control lever articulated on the rear of the skate. In an alternative embodiment, the braking device is formed of the control lever connected on one side to the cuff of the boot and on the other side to a rotating brake pad mounted on the axis of rotation of the rear wheel, a braking rod assembly connects this first pad to other brake pads rotatably mounted on the axles of other wheels, one surface of said pads, opposite the contact surface with the wheel, including ramps co-operating with elements projecting inside the frame so that by acting on the control lever, the rotating pads are brought against return springs in the direction of a lateral surface of each of the wheels provided with pads to brake them.
In another variant, two brake rods placed on each side and over the length of the row of wheels at the level of their axis of rotation include longitudinal elongated holes so as to be able to slide on the rotational axles and a certain number of ramps acting as brake pads placed facing each wheel so that by acting on the control lever the rod slides forwards against return means bringing the ramps into contact with a lateral surface of each wheel.
One drawback of such a device is that the braking force is applied directly at the level of the rotational axles of said wheels or on the periphery of said wheels which causes excessively abrupt braking and wears the wheels or brake pads too quickly. This thus does not allow pressure on the discs to be differentiated as a function of the position of the wheels on the skate. These solutions do not offer the possibility of progressive braking and lack flexibility which, as mentioned, results in the wheels locking and premature wear of the rubber of the wheels.
Accordingly, one object of the invention consists in overcoming the drawbacks of the aforecited braking devices by providing in-line roller skates comprising a braking device which acts gently and progressively.
This object, in addition to others, is achieved by in-line roller skates including at least three wheels mounted on a frame on which is secured a boot and a braking device which includes a control lever articulated on the skate frame, a lateral rod carrying brake pads guided lengthways on the frame and return means to bring the rod into a rest position, a backwards movement of the boot or leg of a user driving the lever which pushes the rod longitudinally against return means into a wheel braking position, the skate being characterized in that at least one ramp is provided on the guide path of the rod so that, when the brake device is actuated, the rod moves forwards against the return means in the direction of discs mounted on a lateral surface of the wheels to bring the brake pads into contact with the discs, said ramp being mounted on the rod or at least on a guide member of the frame between two axles of neighboring wheels so that the braking force imposed on the brake pads against the disc is applied at a point of the rod in proximity to the ramp, while allowing the rod to bend between the brake pads in contact with the discs to assure gradual braking, and in that the rod carrying the brake pads and guided in the longitudinal direction is placed above the axles of the wheels so that the brake pads touch an upper surface of each disc of the wheels so that at the moment of contact of the pads on the discs, the rotation of the wheels in the direction of movement of the skate can drive the rod forwards in the direction of the wheels, independently of the action of the control lever, via friction of the pads on the discs to assist braking and to cause the rod pads to clamp against the disc.
One advantage of the braking device consists in using the wheels"" rotation to drive the rod carrying the brake pads forwards, via friction, against return means, as soon as said pads come into contact with each disc of the wheels, and thus to apply the pads gradually and with more force against the discs to assure self-braking as a result of the movement imposed by the ramps on said rods.
Another advantage of the braking device consists in applying the braking force to the pads at points on the rod located between the axles of two neighboring wheels, and relying on the resilience of the metal rod to assure gentle and gradual braking. In the event that the skate has four wheels, there must be at least two ramps on the rod located between the axles of two neighboring wheels. The first ramp is thus located between the two rear wheels and the second ramp is located between the two front wheels. For a five wheel skate, two rod ramps are used for the three rear wheels, while a third ramp is used between the two front wheels.
One may envisage placing the ramps so as to obtain differential braking. In order to do this, the ramp located between two neighboring wheels may be set off-center, which results in the braking force of the closest pad to the ramp being greater than the braking force of the pad furthest from said ramp.
Braking occurs on discs made, for example, of steel arranged on at least one flank of the wheels via brake pads which are generally made of graphite. An insulating gasket is inserted between this metal disc and the surface of the wheel in order to prevent the heating of the discs during braking being communicated to the wheel rubber. As previously described, it is difficult to brake via the wheels, since the braking power on said wheels has to be apportioned as a function of the possible adherence of the wheels to the ground. This adherence depends on several factors, which are for example the gripping quality of the rubber, the diameter of the wheel, the number of wheels braked, features of the ground and the braking device formed by the material of the discs and pads, and the pressure generating mechanism which must be gradual.
On the other hand, in order to brake via discs, care must be taken not to lock the wheels abruptly, since, in such case, a flat portion is formed on the rolling surface of the wheels which quickly makes them unusable. This also depends on the skater""s weight and the size and material of the wheels used. Moreover, account must also be taken of the heating of the discs which can unnecessarily heat the wheels by inserting for example an insulating gasket mentioned hereinbefore. For all these reasons, braking applied to the largest possible number of wheels of the skates provides an additional advantage. By this observation of the advantage of braking on the largest possible number of wheels, braking occurs on all four or five wheels of one of the skates or more if the skate has more wheels.
Braking by scissoring the legs is one of the only ways of maintaining sufficient stability, which allows braking with a single skate, i.e., that of the front leg.
Braking tests with only two wheels have been performed. This method remains acceptable only to slow down on a relatively flat road, which is not possible on a much steeper road. Further, significant wear of the rear wheels occurs, since the gripping possibility of two wheels with respect to the ground wears evenly the wheels the most pressed against the ground. This is why, it is preferable to brake all the wheels of the skate to prevent any surprise resulting from any irregularity in the ground.